The thing about herpes is that it can lay dormant until something creates a flare up. I have had cold sores all my life. But it's impossible to tell exactly when or where I originally got it.

Also, there are 2 types. Both can be found practically anywhere on the body. Just one PREFERS to be on the mouth and the other on the genitals, but it is possible to get both types anywhere. Just like it is possible to spread oral herpes through oral sex. It's possible to touch a sore on your mouth and then an open sore elsewhere and spread it.....

It's just sooo variable it's hard to tell. I'm sorry you're going through this and I'm here for you. As far as knowing whether he has cheated, your gut is more reliable than anything else. How do you feel in your gut and in your heart?